The present invention relates to the protection of surfaces and in particular steel beams and columns in commercial buildings from twisting due to fire and in particular related to a fire retardant composition which may be sprayed onto the surfaces of the steel beams and columns from conventional spray equipment.
Heretofore, for their protection from twisting in a fire in commercial buildings steel columns and beams have inter alia been coated with a wet mixture of cement and rockwool and such a coating, which is normally sprayed onto the columns from specially designed spray equipment, has been found to be very effective in stopping the steel columns and beams from twisting and being subjected to fire compositions and readily passes the steel column fire endurance test.
However, the appearance of the coating is poor and it is necessary when a good appearance is required, i.e., where the beam or column is visible in occupied parts of the building to further treat the surface of the steel column to improve its appearance. Further, the use of an aqueous mixture of cement and rockwool involves the use of a substantial amount of water which makes the process of coating the columns very messy and due to the presence of large amounts of water there is dripping of the coated columns. This limits the areas of the buildings in which the beams and columns can be coated. In particular, it is not desirable to coat steel columns and beams with this mixture in areas where the interior decoration of the building has been effected.
It is also known to coat the steel columns and beams with a mixture of alkali-metal silicate, rockwool and paper fibers. However, it is found that the rockwool, due to its low melting point, tends to melt when subjected to fire and the composition does not pass the steel column fire endurance test.
It is an object of the present invention to provide a composition which may be sprayed onto steel columns and beams in buildings irrespective of their location, involving the use of minimum amounts of water, thus not causing any significant mess problems in application of the coating and at the same time to provide a good appearance in the finished steel column or beam and further to provide efficient protection to avoid twisting of the steel column or beam under fire conditions and thus be able to pass the steel column fire endurance test.